Face specificity and visual expertise
The face is undoubtedly a special kind of visual stimulus for the human brain. However, the old question of whether face processes can be recruited (at least to some extent) in aduthood to process other visual objects following visual expertise training, remains hotly debated.
We have contributed to this debate by performing ERP studies in which the amplitude of the N170 face-sensitive component in response to a face presented in periphery is reduced in human observers fixating an object of expertise (e.g., Greebles in Greeble experts, or Cars in Car experts).
These studies suggest that nonface object representations compete with face representations as early as the perceptual encoding stage (indexed by the N170). The interest of ERPs here, compared to fMRI studies of visual expertise, is precisely that we can tackle the perceptual stage of face encoding, and that vsual expertise effects cannot be attributed to late processes.
Although visual expertise studies have been somewhat criticized for the smaller size of effects and lack of replication, the results obtained here in a very simple paradigm and are extremely robust and replicable (see Rossion et al., 2004; Rossion et al., 2007). The magnitude of competition/interference effect si also nicely correlated with the level of expertise of our participants (Rossion et al., 2007).
More recently, we showed that visual expertise with cars may lead to an increased inversion effect for pictures of cars, but only in the best experts of our sample (Rossion & Curran, 2010).
Rossion, B. & Curran, T. (2010). Visual expertise with pictures of cars correlates with RT magnitude of the car inversion effect. Perception, 39, 173-183. [PDF]